In fact, there are many assessment factors that will determine the market price of a player, including Osimhen. Apart from the factors that influence a player market price, what actually determines Osimhen price the most is the team need for a player like Osimhen. Simply put, we can see the process of Harry Kane transfer to Bayern Munchen, Tuchel really wanted him and continued to make price offers until an agreement was reached with Tottenham. I think that kind of scenario could also apply to Osimhen, there are definitely some clubs who are a little crazy in spending their budget to recruit Osimhen, they seem to not want to worry about the price, what is important for them is that the player they are targeting can be brought in, like PSG or Chelsea.
I think Osimhen will be up for grabs in the transfer window and Napoli clearly don't want to let go of their asset at a cheap price. Even though the number of goals scored by Osimhen in Serie A has currently decreased from the previous season, it will not have much of an impact on his bargaining value. When a club needs a ready-made, pure striker like Osimhen, their habit is to only think about how to avoid FFP sanctions, not to negotiate a cheaper price.
But if that was true then Real Madrid would have filled the gap since they had the need for a striker more than any other club, or let's say from the top teams in Europe they were the one team starting into the new season without a world class striker. They could have tried to buy Osimhen if they thought he would be this perfect striker they were looking for, but they didn't. I haven't really heard about any impressive offers for Osimhen despite the great season he played. I don't see him in the price range of 150.0 million. I think he should be much cheaper than that, but I understand that the market is inflated.